body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
}

.game-container {
    text-align: center;
}

#score, #level {
    font-size: 20px;
    margin: 10px 0;
}

#game-board {
    display: grid;
    gap: 5px;
    margin: 20px auto;
}

.card {
    width: 80px;
    height: 80px;
    background-color: #3498db;
    background-size: cover;
    background-position: center;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: transform 0.3s;
}

.card.flipped {
    background-color: #2ecc71;
    transform: rotateY(180deg);
}

.card.matched {
    background-color: #e74c3c;
    cursor: default;
}

#hint, #restart {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    margin: 5px;
}

#ranking {
    margin-top: 20px;
}

#ranking-list {
    list-style-position: inside;
    padding: 0;
}
